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<title> JE HA </title>
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<div id="index">
Berkeley DB Java Edition High Availability (JE HA) enables replication of JE
environments.  JE HA is an embedded database management
system designed to provide fast, reliable, and scalable data
management. A JE environment is replicated across the nodes of a
single read/write Master, multiple read only Replica Replication
Group. JE HA is used to improve application availability, provide
improved read performance, and increase data durability.
<h3>Getting Started</h3>
The 
<a href="{@docRoot}/../ReplicationGuide/index.html"
target="_top">Replication
Guide</a> is invaluable for understanding the capabilities of JE HA
and how best to design your replicated application.
<blockquote>
<p>
The
<a
href="{@docRoot}/../ReplicationGuide/introduction.html"
target="_top">Introduction</a>
covers terminology, the replication group
lifecycle, and the concepts of durability and consistency. Much of the
javadoc refers to the topics covered there.
<p>
<a
href="{@docRoot}/../ReplicationGuide/progoverview.html" target="_top">Replication
API First Steps</a> explains how to configure and start a replication
group.
<p>
<a
href="{@docRoot}/../ReplicationGuide/txn-management.html" target="_top">Transaction Management
</a> highlights the tradeoffs that must be considered in a replicated
application and provides some use cases.
</blockquote>
In addition, the 
<a href="{@docRoot}/../examples/je/rep/quote/package-summary.html">je.rep.quote</a> example
package provides three example replication applications.

<h3>What the com.sleepycat.je.rep package contains</h3>
<h5>Replication control</h5>
<ul>
 <li><code>ReplicatedEnvironment</code> is the main access point to
 replication.</li>
 <li><code>ReplicationConfig</code> and
 <code>ReplicationMutableConfig</code> specify attributes of the
 replication system.</li>
</ul>
<h5>Administration</h5>
<ul>
 <li>
 <code>ReplicationNode</code> and <code>ReplicationGroup</code> supply
 administrative views of the replication system.
 </li>
</ul>
<h5>Support</h5>
<ul>
 <li>
 <code>StateChangeListener</code> and <code>StateChangeEvent</code>
 implement a Listener pattern for tracking changes in the replication system.
 </li>
 <li>
 <code>CommitPointConsistencyPolicy</code>,
 <code>TimeConsistencyPolicy</code> and
 <code>NoConsistencyPolicy</code> let the user control the read only
 replica's view of the the replicated data.
 </li>
 <li>
 <code>ReplicatedEnviromentStats</code> provide feedback on system execution.
 </li>
</ul>

<h3>Related Packages</h3>
<ul>
<li>
<a href="{@docRoot}/com/sleepycat/je/rep/monitor/package-summary.html">com.sleepycat.je.rep.monitor</a> lets the application track
the replication system in order to do tasks such as load balancing and
write request routing.
</li>
<li>
<a href="{@docRoot}/com/sleepycat/je/rep/util/package-summary.html">com.sleepycat.je.rep.util</a> provides command line and
programmatic APIs for administering and starting up a replication
system.
</li>
</ul>
<h3>Related Documentation</h3>
@see <a href="{@docRoot}/../ReplicationGuide/index.html" target="_blank">Replication Guide</a>
@see <a
href="{@docRoot}/../examples/je/rep/quote/package-summary.html">
 JE HA Examples</a>
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